Saturday, January 11, 2014

Cultivate crops and build solar PV on the same farmland

You may have ran out of space (or land) for installing solar PV and you don't want to mess up your roof with the heavy PV modules, but that should not deter you from finding ways to take part in the renewable energy initiative by the government.

So, you started to innovate.

Take a look at this efforts by Japanese farmers. They mixed solar farming with cash crop farming. They keep the traditional farming on their agricultural lands but at the same time reap the benefit via Feed-in Tariff mechanism for generating electricity from solar.

Akira Nagashima, a retired engineer, studied and found that the rate of photosynthesis increases as the irradiance level is increased; however at one point, any further increase in the amount of light that strikes the plant does not cause any increase to the rate of photosynthesis.

By knowing that too much sun won’t help further growth of plants, Nagashima came up with the idea to combine PV systems and farming. He devised and originally patented special structure, which is much like a pergola (shaded walkway) in a garden.

He created a couple of testing fields with different shading rates and different crops. The structures he created are made of pipes and rows of PV panels, which are arranged with certain intervals to allow enough sunlight to hit the ground for photosynthesis.

The concept of co-existing farmland and solar PV was first developed by a retired engineer, Akira Nagashima. Photo via REW

Takazawa's solar sharing farm. Photo via REW

Installation cost and FiT rate

In the case of Makoto Takazawa (the first picture above) the cost of the system producing 35,000 kWh annually is about ¥12.6 million (around $126,000). Having secured the first available FIT rate of ¥42/kWh for 20 years, he will earn ¥1.6 million (around $16,000) annually while only making ¥100,000 (around $1,000) annually from farming.

Converted to Malaysian Ringgit, that would be about RM392,000 in installation cost. FiT rate is around RM1.308/kWh and he gets RM49,800 annually from this venture.